This invention relates generally to pet foods, and more particularly, to a dry pet food product that is nutritious for the animal and presents a desirable appearance to the consumer, yet is consistently and economically prepared in commercial operations.
Pet foods are generally manufactured and available in dry, moist, and semi-moist formulations. Moist pet foods, having a moisture content of about 50 percent or greater, are typically prepared from proteinaceous materials such as meat, meat by-products or fish. Such high-moisture pet foods are usually appealing to the animals, but suffer fromm disadvantages of high production cost and a potential for biological instability (spoilage), so that high-moisture pet foods are packaged in cans and must be consumed relatively soon after the containers are opened. Semi-moist products, which typically contain about 15 to 50 percent moisture, are formed from a combination of farinaceous materials, such as wheat or other grains, and proteinaceous materials. The products also contain flavorings and moisture to improve the palatability. However, semi-moist foods also suffer from potential biological instability, requiring sealed packaging such as foil pouches, and such products also must be consumed relatively soon after the container is opened.
Dry pet foods, which typically contain less than about 15 percent moisture, are formed primarily from farinaceous materials, and may contain small amounts of proteinaceous material and flavorings to improve palatability, as well as nutrients to ensure a proper diet for the animal. While dry pet foods have excellent biological stability and can be packaged in bulk containers that need not be used immediately after opening, such dry pet foods also are often relatively low in palatability for the animal and low in perceived attractiveness to the consumer who purchases the product.
Several approaches for improving the palatability and consumer appeal of dry pet foods have been undertaken. In one, the dry pet food is coated with gravy-forming ingredients, so that when water is added a thick gravy is formed. In another approach the dry farinaceous core is covered with a coating of a moist proteinaceous material to mask the core. However, such products suffer from many of the disadvantages inherent in high moisture products. In yet another approach, as described in U.S. Pat. No. 4,229,485, a farinaceous core is covered with a coating of slurried liver, which is then dried on the surface of the core to improve the palatability of the final product and to impart a sheen to the product, which is desirable to the consumer. In such liver-coated dry pet food products, it has been found necessary that the liver content should exceed about 50 percent by weight of the coating so that the final dried product has the desired sheen.
Although the liver coated dry pet food product described in U.S. Pat. No. 4,229,485 has proved successful commercially, it suffers from several disadvantages. The appearance of the product can vary from batch to batch due to variations in the liver quality and minor processing variations. The relatively high lever content necessary to produce the sheen necessitates a high formulation cost, and a high production cost due to relatively long drying times to reduce the moisture content of the coating to a level which will not support biological instability. Further, the desirable surface sheen is obtained only with a liver coating, and not for many other possible proteinaceous ingredients. Accordingly, there has been a need for a pet food product having the inherent advantages of dry pet foods and the improved appearance and palatability of a liver-coated dry pet food, yet allowing low cost, consistent preparation from batch to batch using a variety of proteinaceous ingredients. The present invention fulfills this need and further provides related advantages.